国际交流英语-演讲

Results and discussion
Microstructure of diphasic mullite: (a) aerogel and (b) xerogel.
Results and discussion
Mullite ceramics sintered by (a) microwave (13OO℃ ~ 10 min) and (b, c, d) conventional (b, c: 1300°C~ 10 min; d: 5 ℃ /min to 1320°C without holding) methods. Sample (c), made from diphasic xerogel is opaque, while the rest made from aerogel show transparency.
The key factor
• The aerogel of mullite stoi-chiometry • Free of agglomeration • Highly active
Thanks for your attation
Βιβλιοθήκη Baidu
Experiment
a) Synthesis of diphasic mullite precursors b) Sintering c) Characterization
Results and discussion
Microstructure of diphasic mullite: (a) aerogel and (b) xerogel.
Conclusion
• X-ray diffraction showed that conventionally sintered samples were nearly amor- phous (only a very weak diffraction peaks of δAl2O3, and mullitization had not yet taken place), whereas the microwave-sintered sample was trans- parent and consisted of highly crystalline mullite.
Transparent mullite ceramics from diphasic aerogels by microwave and conventional processings
Speechmaker：Feng Qingfu
Catalog
• Background
• Experiment
• Results and discussion
Background
Hense mullite glass-ceramics have been the best and most realistic choice. • The sol-gel technique • Microwave heating of ceramics A combination of mi- crowave processing with aerogel precursor based on diphasic materials made it possible to achieve trans- parent mullite ceramics in the current study.
• Conclusion
Background
Mullite (3Al,O, . 2Si0,) is by far the most widely used ceramic material . • high melting point (1850°C ) • low thermal expansion coefficient • low thermal conductivity • excellent thermal-shock resis- tance • high strength • good creep resistance,etc.